Wireless communication between electronic devices requires that devices participating in the communication, for example a base station and a mobile station, are configured to conform to an agreed framework for communication. The agreed framework comprises defined procedures that are used to effect the communication in the framework context, wherein the context may comprise for example air interface resources, or radio resources, such as at least one frequency band. Such frameworks may be known as radio access technologies, or RATs. A RAT may be defined in industry standards that device manufacturers can refer to when designing products such that they are capable of communicating according to the RAT.
When standards are used correctly, interoperability between devices from a plurality of suppliers may be achieved. For example, a cellular telephone produced by a first manufacturer may be capable of communicating with a cellular telephone produced by a second manufacturer, using a base station produced by a third manufacturer and a core network produced by a fourth manufacturer.
A mobile station attached to a RAT, in other words a network operating in accordance with the RAT, may form a plurality of separate connections, or flows, to the RAT. For example, a mobile may have concurrently active a voice call and two data flows with different characteristics. The data flows may have requirements that depend on the character of the flows, for example a streaming media flow may require a steady, high bitrate whereas an email updating flow may work with lower bitrate but may have encryption support as a mandatory requirement.
A mobile station may be configured with a policy enabling the mobile to determine for each flow a priority order of available RATs. By evaluating available RATs against the policy and active flows, the mobile may derive for each flow a priority order between the available RATs. Acting on the priority order, a mobile may determine to transfer one or more flows to a more preferable RAT. For example, where the mobile is attached to a cellular RAT with slow datarates and high cost per megabyte, it may determine to transfer a high-bandwidth flow to an available wireless local area network, WLAN, RAT. After the transfer, the mobile may have concurrent flows to more than one RAT.